1. Field of the Invention
The present invention relates to a refrigerating machine that has an outdoor unit and a plurality of indoor units and can carry out heating operation or cooling operation on these plural indoor units at the same time or carry out heating operation and cooling operation in a mixture style, and an intermediate-pressure receiver that is used in the refrigerating machine concerned and carries out gas-liquid separation of gas-liquid mixture refrigerant.
2. Description of the Related Art
There is generally known a refrigerating machine in which an outdoor unit is a plurality of indoor units through an inter-unit pipe comprising a high-pressure gas pipe, a low-pressure gas pipe and a liquid pipe to enable cooling operation or heating operation to be carried out on the plural indoor units at the same time or to enable both cooling operation and heating operation to be carried out on the plural indoor units in a mixing style (see Japanese Patent No. 2804527). In this specification, it is assumed that the refrigerating machine contains a heat pump.
In this type of refrigerating machine, when the temperature of a heat source heat-exchanged with refrigerant in a high-pressure side heat exchanger used as a radiator increases, the compression driving force is increased, the performance of evaporating heat transfer is lowered and the pressure loss in an evaporator is also increased, so that the performance of the refrigerating machine is lowered.